Image pickup element, image pickup apparatus, and method and program for controlling the same

Abstract

An image pickup element generates an AF evaluation value to be used for image-pickup in accordance with an image signal corresponding to a voltage signal obtained from a first pixel group among a plurality of pixels. The image pickup element further outputs an image signal corresponding to a voltage signal obtained from a second pixel group among the plurality of pixels as a live-view display signal for image display. In accordance with the AF evaluation value, a control unit controls a mechanical optical unit having a focus lens and performs live-view display on an image display unit in accordance with the live-view display signal.

What is claimed is: 
     
       1. An image pickup element for picking up an optical image focused thereon and outputting an image signal corresponding to the optical image, comprising:
 a first chip including a plurality of pixels arrayed in a matrix, configured to output an image signal corresponding to the optical image; and 
 a second chip including a control information generation unit and an output unit, 
 wherein the control information generation unit is configured to generate control information to be used for image-pickup in accordance with a first image signal which is obtained from a first pixel group among the plurality of pixels and output the control information in synchronization with a first synchronization signal, and 
 the output unit is configured to output, as an image display signal for image display, a second image signal which is obtained from a second pixel group among the plurality of pixels in synchronization with a second synchronization signal different from the first synchronization signal. 
 
     
     
       2. The image pickup element according to  claim 1 , wherein the first pixel group contains pixels from rows of the array in the matrix that are different from rows of the array containing pixels of the second pixel group. 
     
     
       3. The image pickup element according to  claim 1 , wherein the second chip comprises a switching unit configured to selectively provide the first image signal to the control information generation unit, and wherein the switching unit is configured to, in a preparation state before image-pickup is performed, provide the first image signal to the control information generation unit. 
     
     
       4. The age pickup element according to  claim 3 , wherein when image-pickup is performed, the switching unit is further configured to provide the first image signal to the output unit, and the output unit is configured to output the first image signal and the second image signal as an image-pickup signal. 
     
     
       5. An image pickup apparatus, comprising:
 an image pickup element for picking up an optical image focused thereon and outputting an image signal corresponding to the optical image, the image pickup element including a first chip including a plurality of pixels arrayed in a matrix, configured to output an image signal corresponding to the optical image, and a second chip including a control information generation unit and an output unit, wherein the control information generation unit is configured to generate control information to be used for image-pickup in accordance with a first image signal which is obtained from a first pixel group among the plurality of pixels and output the control information in synchronization with a first synchronization signal, and the output unit is configured to output, as an image display signal for image display, a second image signal which is obtained from a second pixel group among the plurality of pixels in synchronization with a second synchronization signal different from the first synchronization signal; 
 a control unit configured to control, upon receipt of the control information, image pickup in accordance with the control information; and 
 a display control unit configured to perform live-view display in accordance with the image display signal. 
 
     
     
       6. The image pickup apparatus according to  claim 5 , further comprising:
 a readout control unit configured to read out the first pixel group at a first frame rate and to read out the second pixel group at a second frame rate that is less than the first frame rate. 
 
     
     
       7. The image pickup apparatus according to  claim 6 , wherein the readout control unit is configured to operate in both a first image-pickup mode for reading out the first pixel group and a second image-pickup mode for reading out the second pixel group. 
     
     
       8. The image pickup apparatus according to  claim 7  wherein the readout control unit is configured to start the first image-pickup mode and the second image-pickup mode simultaneously. 
     
     
       9. The image pickup apparatus according to  claim 5 , wherein the control information generation unit is configured to generate, as the control information, an auto-focus evaluation value for use in performing auto-focus control, and the control unit is configured to perform drive control of a focus lens in accordance with the auto-focus evaluation value. 
     
     
       10. The image pickup apparatus according to  claim 7  wherein the control information generation unit is configured to generate, as the control information, an auto-focus evaluation value for use in performing auto-focus control, the control unit is configured to determine whether or not the auto-focus evaluation value satisfies a predetermined evaluation condition, and if the control unit determines that the evaluation condition has been satisfied, the readout control unit is configured to terminate the first image-pickup mode. 
     
     
       11. The image pickup apparatus according to  claim 5 , wherein the control information generation unit is configured to generate, as the control information, a white balance coefficient to be used in performing white balance correction, and the control unit is configured to perform correction processing of the image signal output from the image pickup element in accordance with the generated white balance coefficient. 
     
     
       12. The image pickup apparatus according to  claim 5 , further comprising:
 a light emission unit configured to emit light to illuminate an object for image pickup, 
 wherein the control information generation unit is configured to generate, as the control information, a light emission control amount for controlling a light emission amount of the light emission unit, and 
 the control unit is configured to, when image-pickup is performed by using the light emission unit, make the light emission unit perform a pre-emission to obtain the light emission control amount from the control information generation unit, and then make the light emission unit perform a main light emission in accordance with the light emission control amount to perform image-pickup. 
 
     
     
       13. An image pickup apparatus, comprising:
 the image pickup element according to  claim 4 , where the control information generation unit is configured to generate, as the control information, an auto-focus evaluation value to be used in performing auto-focus control; 
 a control unit configure to perform, upon reception of the auto-focus evaluation value, drive control of a focus lens in accordance with the auto-focus evaluation value; and 
 a display control unit configured to perform live-view display in accordance with the image display signal, 
 wherein the control unit is further configured to, when an auto-focus mode for performing the auto-focus control is set, control the switching unit to provide the first image signal to the control information generation unit. 
 
     
     
       14. A method for controlling an image pickup apparatus including an image pickup element for picking up an optical image focused thereon and outputting an image signal corresponding to the optical image, the image pickup element including a first chip including a plurality of pixels arrayed in a matrix, configured to output an image signal corresponding to the optical image, and a second chip including a control information generation unit and an output unit, wherein the control information generation unit is configured to generate control information to be used for image-pickup in accordance with a first image signal which is obtained from a first pixel group among the plurality of pixels and output the control information in synchronization with a first synchronization signal, and the output unit is configured to output, as an image display signal for image display, a second image signal which is obtained from a second pixel group among the plurality of pixels in synchronization with a second synchronization signal different from the first synchronization signal, the method comprising:
 controlling, upon reception of the control information, image-pickup in accordance with the control information; and 
 performing live-view display in accordance with the image display signal. 
 
     
     
       15. A non-transitory computer readable storage medium for causing one or more processors included in an image pickup apparatus to execute a method of controlling the image pickup apparatus, the image pickup apparatus including the image pickup element for picking up an optical image focused thereon and outputting an image signal corresponding to the optical image, the image pickup element including a first chip including a plurality of pixels arrayed in a matrix, configured to output an image signal corresponding to the optical image, and a second chip including a control information generation unit and an output unit, wherein the control information generation unit is configured to generate control information to be used for image-pickup in accordance with a first image signal which is obtained from a first pixel group among the plurality of pixels and output the control information in synchronization with a first synchronization signal, and the output unit is configured to output, as an image display signal for image display, a second image signal which is obtained from a second pixel group among the plurality of pixels in synchronization with a second synchronization signal different from the first synchronization signal, the method comprising:
 controlling, upon reception of the control information, image-pickup in accordance with the control information; and 
 performing live-view display in accordance with the image display signal. 
 
     
     
       16. The image pickup apparatus according to  claim 8 , wherein the control information generation unit is configured to generate, as the control information, an auto-focus evaluation value for use in performing auto-focus control,
 the control unit is configured to determine whether or not the auto-focus evaluation value satisfies a predetermined evaluation condition, and 
 if the control unit determines that the evaluation condition has been satisfied, the readout control unit is configured to terminate the first image-pickup mode. 
 
     
     
       17. The image pickup element according to  claim 1 , the second chip further comprising a converter configured to convert the image signal into a digital signal. 
     
     
       18. The image pickup element according to  claim 1 , wherein the first chip and the second chip are arranged in a stacked structure. 
     
     
       19. The image pickup element according to  claim 18 , wherein the first chip is positioned on the side at which the optical image is received.